Circuit arrangement for producing a high voltage spark

ABSTRACT

A circuit arrangement for producing a high voltage spark comprising a semi-conductor device and a transducer coupled therewith, a source of low power d.c. voltage coupled to the semi-conductor device for supplying power thereto, the transducer having a primary and a secondary circuit, a rectifier and a storage capacitor connected into the secondary circuit of the transducer, a sparkgap device connected in parallel with the secondary circuit of the transducer, a switching device having a plurality of switching positions, the transducer including an auxiliary winding connected in circuit relationship with the storage capacitor in one of the switching positions wherein the storage capacitor is charged to a voltage defined by the transformation ratio of the transducer, and in another position of the switching device the capacitor discharges the voltage thereon across a diode into the sparkgap device connected in parallel with the secondary circuit of the transducer, the transducer including a feedback coupled winding returned to an electrode of the semi-conductor device.

[ Aug.7, 1973 1 CIRCUIT ARRANGEMENT FOR PRQDUCING A man VOLTAGE sPARKPeter Lohberg, Rodheim v.d.l-l.,

[75] lnven-tor:

' Germany v A [73] Assignee: Braun Aktiengesellschaft,

Frankfurt/am Main, Germany 221 Filed: 'July23, 1971 211 Appl. No.2165,081

[30] Foreign Application Priority Data July 27, 1970 Germany....'. P 2037 068.7

[52] US. CL... 315/209 T, 315/209 CD, 315/227 R, I 315/239, 315/244 [5l] Int. Cl "05b [58} Field of Search 3 l5/36, 209 R, 209 T, 315/209 CD,226, 227 R, 244, 239; 123/148 [56! References Cited UNITED STATESPATENTS 3,056,066 9/1962 Dozier 315/239 UX Primary E xaminer1 loy LakeAssistant Examiner-James B. Mullins Attorney-Ernest F. Marmorek [57ABSTRACT A circuit arrangement for producing a high voltage sparkcomprising a semi-conductor device and a transducer coupled therewith, asource of low power d.c. voltage coupled to the semi-conductor devicefor supplying power thereto, the transducer having a primary and asecondary circuit, a rectifier and a storage capacitor connected intothe secondary circuit of the trans- I ducer, a sparkgap device connectedin parallel with the secondary circuit of the transducer, a switchingdevice having a plurality of switching positions, the transducerincluding an auxiliary winding connected in circuit relationship withthe storage capacitor in one of the switching positions wherein thestorage capacitor is charged to a voltage defined by the transformationratio of the transducer, and in another position of the switching devicethe capacitor discharges the voltage thereon across a diode into thesparkgap device connected in parallel with the secondary circuit of thetransducer, the transducer including a feedback coupled winding returnedto an electrode of the semiconductor device.

2 Claims, 1 Drawing Figure nnunn IGNITOR FOR USE WITH A LIGHTER FIELD OFTHE INVENTION The present invention relates to a circuit arrangement forproducinga high voltage spark which substan- .2 Furthermore, the energybalance is also in favor of the circuit arrangement according to thepresent inven- I tion which, in the ideal case, can'have an efficiencyof tially comprises ablocking oscillator or transducer circuitconsisting of a transistor anda transducer supplied from a source of lowdc. voltage, such as a battery or an accumulator, and wherein in thesecondary circuit of the transformer adiode device and a storagecapacitor are connected.

BACKGROUND OF THE INVENTION There are known circuits for producing thespark voltage or spark in a gas lighter device in which the energyforthe ignition spark is taken off from a dry cell constitutingthe sourceof low power dc. voltage. The relatively high ignition voltage isproduced by a transformer the turn ratio of which corresponds to'thevolt-' age ratio developed. V

The above requirement in the case,fore xample, of gas lighters requiresthat the transformer is provided on its primary side with 6 and 'on thesecondary side with 6,000 turns, which has the disadvantage that suchtransformers are relatively large, expensive and sensitive, as'heav'yinsulation isrequired on them due to the presence of the highsecondaryvoltage.

In known lighter devices the, 6,000 turns of the secondary winding aremadeo f'a wire having a diameter of 0.05' to 0.02 mm which itselfrepresents a'very diffi- .cult technological problem and still it cannotbe prevented that the space available for the gas tank is very limiteddue to the space requirement of the ignition circuit. I r

SUMMARY OF Tl-IE INVENTION It is, therefore, an object of the presentinvention substantially to-reduce the entire volume and, thereby,-

the dimensions and the space requirement of such spark producing circuitarrangement.

In accordance with the present invention, a sparkgap means lies inparallel with the secondary winding of the transducer and wherein bymeans of a mechanical or electrical multi-pole switching means theprimary winding and/or the feedback winding of the transducersimultaneously ,can be disconnected or the storage capacitor can becoupled to an auxiliary winding of the transducer and wherein thevoltage of the storage ca- 1 pacitor during its discharge can be steppedup to the spark voltage of the sparkgap means in accordance with theturn ratio of the auxiliary and the secondary winding of the transducer.

Instead of the usual transformers having a number of turns whichcorresponds to the relationship of the battery voltage and the sparkvoltage, the present invention proposes a double transformation of thevoltage over the feedback coupled transducer and which requires onlyarelatively low number of turns on the auxiliary winding which is alsoloaded only, for a short time. The additional space required for suchwinding is very small.

Special advantages flow from the circuit arrangement according to thepresent invention if it is applied in modern pocket-size lighterdevices, as the space avail able for the ignition circuitin such devicesis very limited.

about 100 percent while the known circuit arrangeefficiency; This fact,especially in the case of using a battery as the energy source, can haveconsiderable advantages.

The high efficiency and the double transformation leads to the resultthat instead of the hitherto used 15V batteries a miniature cell of 1.5Vcan be used in the circuit arrangement according to the presentinvention.

A further advantage of the present invention is manifested in that thedimensioning of the transducer, that is, the number of the turnsrequired for the voltage stored on the storage capacitor, is independentfrom the magnitude of the necessary spark voltage.

BRIEF DESCRIPTION OF THE DRAWING The invention will become more'readilyapparent from the following description of a preferred embodimentthereof shown, by way of example, in the accompanying drawing, in which:I i

The single FIGURE is a circuit diagram of the arrangement for producinga high voltage spark accordingto the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT- With reference to the singleFIGURE illustrating the preferred embodiment of the present invention,the circuit arrangement comprises a primary circuit which is of theconventional blocking oscillator or feedback transducer type, whichsubstantiallycomprises a transistor Q, primary and feedback windings ofa transducerT and a source of dc voltage having a voltage magnitude UThe primary windingof the transducer T is designated by L, while'thefeedback connected winding is designated L In the secondary circuit ofthe transducer T arectifier circuit arrangement is providedconsisting ofa diode D, a storage capacitor C which is usually an electrolyte-typecapacitor, and a sparkgap means F connected parallel therewith.

After turning on the transducer, that is, after closing the contacts S,,S, and establishing the connection by means of the contacts, between thediode D and the capacitor C, the storage capacitor C becomes charged. Assoon as the contacts S, S, are thrown into the posicapacitor C isdischarged through the auxiliary winding L and thereby the voltagenecessary for the ignition is produced across the sparkgap F by thestepping-up activity across the windings LJL Thecontacts S S, are thecontact arms of a mechanical multi-pole switch which can be operatedsimultaneously and which can be replaced by an elec-' tronic switchingelement.

As a result of the discharging of the capacitor C according to the.present invention'over the auxiliary winding L thetotal number of turnswhencornpared with a circuit using a'direct stepping-up of the batterytive total transformation relationshipcan be described voltage to thespark voltage, can be reduced by about percent and thereby thedimensions of the transducer T can substantially also be reduced. Theeffecby the following formula:

rectifying means,

u Wa/Wz Wa/w W3 [W2 capacitor means connected for storing saidtranswherein the indexes relate to the corresponding windformed highervoltage energy, "'8 i 4- an auxiliary winding;

From the above It pp that although the 5 sparkgap means connected inparallel with said secvention has been described hereinbefore withrespect ondary winding; and to a certain embodiment thereof, it isevident that many Second Switching means modfficaimm and Ehanges f saidfirst switching means having a closed position for parting from thespiritof the invention. Accordingly, by connecting Said semi conductivedevice to said the appened claims, I intend to cover all suchmodificatransducer means and respectively, an Open posi f i chailges asfall with". the true Spmt and Scope tion for disconnecting saidsemi-conductive device of thls from said transducer means,

Having thus described the invention, what I claim as new and desire tobe secured by Letters Patent, is as follows:

I claim:

1. In a circuit arrangement for producing a high voltage spark from adirect current source of a low voltage,

in combination: feedback transducer means including a primary circuitand a secondary circuit for transforming energy from said source to ahigher voltage,

said primary circuit comprising a primary winding,

said second switching means being connected to said capacitor means andhaving a closed position for connecting said capacitor means through therectifying means to said secondary winding during the closed position ofsaid first switching means and, respectively, a switch-over position forreleasably connecting said capacitor means to said auxiliary windingduring the open position of said first switching means, therebydischarging the stored energy from the capacitor means through theauxiliary winding and simultaneously inducing a high said So r sparkvoltage in said secondary winding which proa semi-conductive devicehaving conducting and dllces a p rk in d sparkgap means.

non-conducting states, and 2. The circuit arrangement as claimed inclaim 1, for

first switching means; use with a lighter device for producing theignition said secondary circuit comprising spark for igniting a fueltherein.

a secondary winding, 3

1. In a circuit arrangement for producing a high voltage spark from adirect current source of a low voltage, in combination: feedbacktransducer means including a primary circuit and a secondary circuit fortransforming energy from said source to a higher voltage, said primarycircuit comprising a primary winding, said source, a semi-conductivedevice having conducting and non-conducting states, and first switchingmeans; said secondary circuit comprising a secondary winding, rectifyingmeans, capacitor means connected for storing said transformed highervoltage energy, an auxiliary winding; sparkgap means connected inparallel with said secondary winding; and second switching means, saidfirst switching means having a closed position for connecting saidsemi-conductive device to said transducer means and, respectively, anopen position for disconnecting said semi-conductive device from saidtransducer means, said second switching means being connected to saidcapacitor means and having a closed position for connecting saidcapacitor means through the rectifying means to said secondary windingduring the closed position of said first switching means and,respectively, a switch-over position for releasably connecting saidcapacitor means to said auxiliary winding during the open position ofsaid first switching means, thereby discharging the stored energy fromthe capacitor means through the auxiliary winding and simultaneouslyinducing a high spark voltage in said secondary winding which produces aspark in said sparkgap means.
 2. The circuit arrangement as claimed inclaim 1, for use with a lighter device for producing the ignition sparkfor igniting a fuel therein.